Stabilizing Pentacene By Cyclopentannulation. (19th November 2015)

• Record Type: Journal Article
• Authors: Bheemireddy, Sambasiva R.; Ubaldo, Pamela C.; Rose, Peter W.; Finke, Aaron D.; Zhuang, Junpeng; Wang, Lichang; Plunkett, Kyle N.
• Is Part Of: Angewandte Chemie. Volume 127:Number 52(2015)
• Page Start: 15988
• Page End: 15992
• Publication Date: 2015-11-19
• Subjects: Acene -- Konjugation -- Organische Elektronik -- Palladium -- Polycyclische aromatische Kohlenwasserstoffe; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201508650
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: A new class of stabilized pentacene derivatives with externally fused five‐membered rings are prepared by means of a key palladium‐catalyzed cyclopentannulation step. The target compounds are synthesized by chemical manipulation of a partially saturated 6, 13‐dibromopentacene precursor that can be fully aromatized in a final step through a DDQ‐mediated dehydrogenation reaction (DDQ=2, 3‐dichloro‐5, 6‐dicyano‐1, 4‐benzoquinone). The new 1, 2, 8, 9‐tetraaryldicyclopenta[fg, qr]pentacene derivatives have narrow energy gaps of circa 1.2 eV and behave as strong electron acceptors with lowest unoccupied molecular orbital energies between −3.81 and −3.90 eV. Photodegradation studies reveal the new compounds are more photostable than 6, 13‐bis(triisopropylsilylethynyl)pentacene (TIPS‐pentacene). Abstract : Fünferreihe : Eine palladiumkatalysierte Cyclopentanellierung mit anschließender DDQ‐vermittelter Dehydrierung überführt partiell hydrierte Pentacen‐ Vorstufen in stabilisierte Pentacene. Die Produkte sind hervorragende Elektronenakzeptoren mit kleinen Energielücken.